1 /*
2 * Copyright (c) Christos Zoulas 2003.
3 * All Rights Reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice immediately at the beginning of the file, without modification,
10 * this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include "file.h"
29
30 #ifndef lint
31 FILE_RCSID("@(#)$File: magic.c,v 1.121 2023/02/09 17:45:19 christos Exp $")
32 #endif /* lint */
33
34 #include "magic.h"
35
36 #include <stdlib.h>
37 #ifdef HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 #include <string.h>
41 #ifdef QUICK
42 #include <sys/mman.h>
43 #endif
44 #include <limits.h> /* for PIPE_BUF */
45
46 #if defined(HAVE_UTIMES)
47 # include <sys/time.h>
48 #elif defined(HAVE_UTIME)
49 # if defined(HAVE_SYS_UTIME_H)
50 # include <sys/utime.h>
51 # elif defined(HAVE_UTIME_H)
52 # include <utime.h>
53 # endif
54 #endif
55
56 #ifdef HAVE_UNISTD_H
57 #include <unistd.h> /* for read() */
58 #endif
59
60 #ifndef PIPE_BUF
61 /* Get the PIPE_BUF from pathconf */
62 #ifdef _PC_PIPE_BUF
63 #define PIPE_BUF pathconf(".", _PC_PIPE_BUF)
64 #else
65 #define PIPE_BUF 512
66 #endif
67 #endif
68
69 #ifdef PHP_WIN32
70 # undef S_IFLNK
71 # undef S_IFIFO
72 #endif
73
74 file_private int unreadable_info(struct magic_set *, mode_t, const char *);
75 file_private const char *file_or_stream(struct magic_set *, const char *, php_stream *);
76
77 #ifndef STDIN_FILENO
78 #define STDIN_FILENO 0
79 #endif
80
81 file_public struct magic_set *
magic_open(int flags)82 magic_open(int flags)
83 {
84 return file_ms_alloc(flags);
85 }
86
87 file_private int
unreadable_info(struct magic_set * ms,mode_t md,const char * file)88 unreadable_info(struct magic_set *ms, mode_t md, const char *file)
89 {
90 if (file) {
91 /* We cannot open it, but we were able to stat it. */
92 if (access(file, W_OK) == 0)
93 if (file_printf(ms, "writable, ") == -1)
94 return -1;
95 #ifndef WIN32
96 if (access(file, X_OK) == 0)
97 if (file_printf(ms, "executable, ") == -1)
98 return -1;
99 #else
100 /* X_OK doesn't work well on MS-Windows */
101 {
102 const char *p = strrchr(file, '.');
103 if (p && (stricmp(p, ".exe")
104 || stricmp(p, ".dll")
105 || stricmp(p, ".bat")
106 || stricmp(p, ".cmd")))
107 if (file_printf(ms, "writable, ") == -1)
108 return -1;
109 }
110 #endif
111 }
112 if (S_ISREG(md))
113 if (file_printf(ms, "regular file, ") == -1)
114 return -1;
115 if (file_printf(ms, "no read permission") == -1)
116 return -1;
117 return 0;
118 }
119
120 file_public void
magic_close(struct magic_set * ms)121 magic_close(struct magic_set *ms)
122 {
123 if (ms == NULL)
124 return;
125 file_ms_free(ms);
126 }
127
128 /*
129 * load a magic file
130 */
131 file_public int
magic_load(struct magic_set * ms,const char * magicfile)132 magic_load(struct magic_set *ms, const char *magicfile)
133 {
134 if (ms == NULL)
135 return -1;
136 return file_apprentice(ms, magicfile, FILE_LOAD);
137 }
138
139 file_public int
magic_compile(struct magic_set * ms,const char * magicfile)140 magic_compile(struct magic_set *ms, const char *magicfile)
141 {
142 if (ms == NULL)
143 return -1;
144 return file_apprentice(ms, magicfile, FILE_COMPILE);
145 }
146
147 file_public int
magic_check(struct magic_set * ms,const char * magicfile)148 magic_check(struct magic_set *ms, const char *magicfile)
149 {
150 if (ms == NULL)
151 return -1;
152 return file_apprentice(ms, magicfile, FILE_CHECK);
153 }
154
155 file_public int
magic_list(struct magic_set * ms,const char * magicfile)156 magic_list(struct magic_set *ms, const char *magicfile)
157 {
158 if (ms == NULL)
159 return -1;
160 return file_apprentice(ms, magicfile, FILE_LIST);
161 }
162
163 #ifndef COMPILE_ONLY
164
165 /*
166 * find type of descriptor
167 */
168 file_public const char *
magic_descriptor(struct magic_set * ms,int fd)169 magic_descriptor(struct magic_set *ms, int fd)
170 {
171 if (ms == NULL)
172 return NULL;
173 return file_or_stream(ms, NULL, NULL);
174 }
175
176 /*
177 * find type of named file
178 */
179 file_public const char *
magic_file(struct magic_set * ms,const char * inname)180 magic_file(struct magic_set *ms, const char *inname)
181 {
182 if (ms == NULL)
183 return NULL;
184 return file_or_stream(ms, inname, NULL);
185 }
186
187 file_public const char *
magic_stream(struct magic_set * ms,php_stream * stream)188 magic_stream(struct magic_set *ms, php_stream *stream)
189 {
190 if (ms == NULL)
191 return NULL;
192 return file_or_stream(ms, NULL, stream);
193 }
194
195 file_private const char *
file_or_stream(struct magic_set * ms,const char * inname,php_stream * stream)196 file_or_stream(struct magic_set *ms, const char *inname, php_stream *stream)
197 {
198 int rv = -1;
199 unsigned char *buf;
200 zend_stat_t sb = {0};
201 ssize_t nbytes = 0; /* number of bytes read from a datafile */
202 int no_in_stream = 0;
203
204 if (file_reset(ms, 1) == -1)
205 goto out;
206
207 /*
208 * one extra for terminating '\0', and
209 * some overlapping space for matches near EOF
210 */
211 #define SLOP (1 + sizeof(union VALUETYPE))
212 if ((buf = CAST(unsigned char *, emalloc(ms->bytes_max + SLOP))) == NULL)
213 return NULL;
214
215 switch (file_fsmagic(ms, inname, &sb)) {
216 case -1: /* error */
217 goto done;
218 case 0: /* nothing found */
219 break;
220 default: /* matched it and printed type */
221 rv = 0;
222 goto done;
223 }
224
225 errno = 0;
226
227 if (inname && !stream) {
228 no_in_stream = 1;
229 stream = php_stream_open_wrapper((char *)inname, "rb", REPORT_ERRORS, NULL);
230 if (!stream) {
231 if (unreadable_info(ms, sb.st_mode, inname) == -1)
232 goto done;
233 rv = -1;
234 goto done;
235 }
236 }
237
238 php_stream_statbuf ssb;
239 if (php_stream_stat(stream, &ssb) < 0) {
240 if (ms->flags & MAGIC_ERROR) {
241 file_error(ms, errno, "cannot stat `%s'", inname);
242 rv = -1;
243 goto done;
244 }
245 }
246 memcpy(&sb, &ssb.sb, sizeof(zend_stat_t));
247
248 /*
249 * try looking at the first ms->bytes_max bytes
250 */
251 if ((nbytes = php_stream_read(stream, (char *)buf, ms->bytes_max - nbytes)) < 0) {
252 file_error(ms, errno, "cannot read `%s'", inname);
253 goto done;
254 }
255
256 (void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
257 if (file_buffer(ms, stream, &sb, inname, buf, CAST(size_t, nbytes)) == -1)
258 goto done;
259 rv = 0;
260 done:
261 efree(buf);
262
263 if (no_in_stream && stream) {
264 php_stream_close(stream);
265 }
266 out:
267 return rv == 0 ? file_getbuffer(ms) : NULL;
268 }
269
270
271 file_public const char *
magic_buffer(struct magic_set * ms,const void * buf,size_t nb)272 magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
273 {
274 if (ms == NULL)
275 return NULL;
276 if (file_reset(ms, 1) == -1)
277 return NULL;
278 /*
279 * The main work is done here!
280 * We have the file name and/or the data buffer to be identified.
281 */
282 if (file_buffer(ms, NULL, NULL, NULL, buf, nb) == -1) {
283 return NULL;
284 }
285 return file_getbuffer(ms);
286 }
287 #endif
288
289 file_public const char *
magic_error(struct magic_set * ms)290 magic_error(struct magic_set *ms)
291 {
292 if (ms == NULL)
293 return "Magic database is not open";
294 return (ms->event_flags & EVENT_HAD_ERR) ? ms->o.buf : NULL;
295 }
296
297 file_public int
magic_errno(struct magic_set * ms)298 magic_errno(struct magic_set *ms)
299 {
300 if (ms == NULL)
301 return EINVAL;
302 return (ms->event_flags & EVENT_HAD_ERR) ? ms->error : 0;
303 }
304
305 file_public int
magic_getflags(struct magic_set * ms)306 magic_getflags(struct magic_set *ms)
307 {
308 if (ms == NULL)
309 return -1;
310
311 return ms->flags;
312 }
313
314 file_public int
magic_setflags(struct magic_set * ms,int flags)315 magic_setflags(struct magic_set *ms, int flags)
316 {
317 if (ms == NULL)
318 return -1;
319 #if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
320 if (flags & MAGIC_PRESERVE_ATIME)
321 return -1;
322 #endif
323 ms->flags = flags;
324 return 0;
325 }
326
327 file_public int
magic_version(void)328 magic_version(void)
329 {
330 return MAGIC_VERSION;
331 }
332
333 file_public int
magic_setparam(struct magic_set * ms,int param,const void * val)334 magic_setparam(struct magic_set *ms, int param, const void *val)
335 {
336 if (ms == NULL)
337 return -1;
338 switch (param) {
339 case MAGIC_PARAM_INDIR_MAX:
340 ms->indir_max = CAST(uint16_t, *CAST(const size_t *, val));
341 return 0;
342 case MAGIC_PARAM_NAME_MAX:
343 ms->name_max = CAST(uint16_t, *CAST(const size_t *, val));
344 return 0;
345 case MAGIC_PARAM_ELF_PHNUM_MAX:
346 ms->elf_phnum_max = CAST(uint16_t, *CAST(const size_t *, val));
347 return 0;
348 case MAGIC_PARAM_ELF_SHNUM_MAX:
349 ms->elf_shnum_max = CAST(uint16_t, *CAST(const size_t *, val));
350 return 0;
351 case MAGIC_PARAM_ELF_SHSIZE_MAX:
352 ms->elf_shsize_max = *CAST(const size_t *, val);
353 return 0;
354 case MAGIC_PARAM_ELF_NOTES_MAX:
355 ms->elf_notes_max = CAST(uint16_t, *CAST(const size_t *, val));
356 return 0;
357 case MAGIC_PARAM_REGEX_MAX:
358 ms->regex_max = CAST(uint16_t, *CAST(const size_t *, val));
359 return 0;
360 case MAGIC_PARAM_BYTES_MAX:
361 ms->bytes_max = *CAST(const size_t *, val);
362 return 0;
363 case MAGIC_PARAM_ENCODING_MAX:
364 ms->encoding_max = *CAST(const size_t *, val);
365 return 0;
366 default:
367 errno = EINVAL;
368 return -1;
369 }
370 }
371
372 file_public int
magic_getparam(struct magic_set * ms,int param,void * val)373 magic_getparam(struct magic_set *ms, int param, void *val)
374 {
375 if (ms == NULL)
376 return -1;
377 switch (param) {
378 case MAGIC_PARAM_INDIR_MAX:
379 *CAST(size_t *, val) = ms->indir_max;
380 return 0;
381 case MAGIC_PARAM_NAME_MAX:
382 *CAST(size_t *, val) = ms->name_max;
383 return 0;
384 case MAGIC_PARAM_ELF_PHNUM_MAX:
385 *CAST(size_t *, val) = ms->elf_phnum_max;
386 return 0;
387 case MAGIC_PARAM_ELF_SHNUM_MAX:
388 *CAST(size_t *, val) = ms->elf_shnum_max;
389 return 0;
390 case MAGIC_PARAM_ELF_SHSIZE_MAX:
391 *CAST(size_t *, val) = ms->elf_shsize_max;
392 return 0;
393 case MAGIC_PARAM_ELF_NOTES_MAX:
394 *CAST(size_t *, val) = ms->elf_notes_max;
395 return 0;
396 case MAGIC_PARAM_REGEX_MAX:
397 *CAST(size_t *, val) = ms->regex_max;
398 return 0;
399 case MAGIC_PARAM_BYTES_MAX:
400 *CAST(size_t *, val) = ms->bytes_max;
401 return 0;
402 case MAGIC_PARAM_ENCODING_MAX:
403 *CAST(size_t *, val) = ms->encoding_max;
404 return 0;
405 default:
406 errno = EINVAL;
407 return -1;
408 }
409 }
410
